eghatch9295

iTrader: (1)

Currently helping a scientist (not really) who for some reason allowed his 97 Civic to be tested on the rollers instead of the obd-2 port. Car is a stock EX, has no CEL, and obviously would have passed the port test. It failed the roller (sniffer) test in a pretty impressive fashion. HC and CO are way up, was slightly over on NOx. Aside from adjusting ignition timing, verifying ignition components condition, and changing the oil (its bad), what else should I look for to get those numbers back down?

Former User

Post the emissions sheet.

Does the CEL work?

There are probably multiple issues, but at the very least the cat is almost surely dead.

eghatch9295

iTrader: (1)

if i can get my hands on it, i will. was texted to me in the following format:

hc 97lim- 272
Co 54lim- 353
Nox749lim- 924

Former User

Were O2 levels measured?

CEL definitely works?

tony_2018

tune up on ignition?

eghatch9295

iTrader: (1)

yes, cel works. was not given o2 information

mk378

If the car has an EGR system, cleaning the EGR valve and passages is important for NOx. Failing all three often means that the catalytic converter is worn out, that may also eventually throw a P0420.

tony_2018

He just said no cel...

eghatch9295

iTrader: (1)

no egr on the ex.

tony_2018

Some maintenance tune up work will probably need to be done. fuel injection cleaner should do the trick or pull them out and send them off to be clean and tested. Ignition system can probably need some replacing as well.

eghatch9295

iTrader: (1)

im going to replace the plugs, swap the working autozone reman dizzy for a known good oe, and retard the ignition timing. retest after those things, will post results. im sure people will question the dizzy swap, but reman units are pure trash. instead of bench testing every component in the POS, i will use one of mine to be sure i have a 100% working unit.

tony_2018

No doubt, my cousin autozone crap died on him not too long ago. He ended up having to replace it again...again....again....until finally 1 kept running

eghatch9295

iTrader: (1)

changed oil, swapped distributors and wires for a set of ngk's, retarded ignition timing significantly. nox nearly cut in half, hc/co both reduced but still way above limit.

tony_2018

cat...bad cat..OR you can try a can of CRC guarantee to pass

eghatch9295

iTrader: (1)

usually high nox is cat, i passed that well under the limit.